Multifunctional Heusler alloy: experimental evidences of enhanced magnetocaloric properties at room temperature and half-metallicity

2015/08/07 by Vivas, R. J. Caraballo, Pedro, S. S., Cruz, C. +5
#FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci)

paper · doi:10.48550/arxiv.1508.01828

Abstract

Heusler alloys are widely studied due to their interesting structural and magnetic properties, like magnetic memory shape ability, coupled magneto-structural phase transitions and half-metallicity; ruled, for many cases, by the valence electrons number (N_v). The present work focuses on the magnetocaloric potentials of half-metals, exploring the effect of N_v on the magnetic entropy change, preserving half-metallicity. The test bench is the Si-rich side of the half-metallic series Fe₂MnSi_1-xGa_x. From the obtained experimental results it was possible to obtain |ΔS|_max=ΔH^0.8(α+βN_v), i.e., the maximum magnetic entropy change depends in a linear fashion on N_v, weighted by a power law on the magnetic field change ΔH (α and β are constants experimentally determined). In addition, it was also possible to predict a new multifunctional Heusler alloy, with enhanced magnetocaloric effect, Curie temperature close to 300 K and half-metallicity.

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